Calculate MQTT signature parameters

When you connect a device to IoT Platform using a custom MQTT client, you must provide the MQTT signature authentication parameters: username, passwd, and mqttClientId.

Overview

Choose one of the following methods to obtain MQTT signature parameters.

Method	Description
Obtain from the IoT Platform console	The supported signature algorithm is hmacsha256. The device's client ID defaults to `${ProductKey} + '.' + ${DeviceName}` and cannot be modified.
Calculate using a web tool	The supported signature algorithms are hmacmd5 and hmacsha1.
Calculate using a Node.js script	The supported signature algorithm is hmacsha256. The device's client ID defaults to `${ProductKey} + '.' + ${DeviceName}` and can be modified.

Obtain from the IoT Platform console

Log on to the IoT Platform console.
On the Overview page, find the instance that you want to manage and click the instance ID or instance name.
In the left-side navigation pane, select Devices > Device to go to the Device page.
Find your device and click View to go to the Device Details page.
On the Device Information tab, click View next to MQTT Connection Parameters to view the MQTT signature parameters.

Important
The clientId parameter here maps to mqttClientId, not the device's client ID. MQTT-TLS communication.

The MQTT Connection Parameters dialog box displays the clientId, username, passwd, mqttHostUrl, and port values. Click Copy All to copy them.

Calculate using a web tool

Download the MQTT_Password tool package and decompress it.
In the MQTT_Password folder, open the sign.html file in a browser.

On the MQTT signature calculation page, enter the required information.

Parameter	Description
productKey	The device certificate saved when you added the device. Device certificate information. View this information on the Device Details page in the console.
deviceName
deviceSecret
timestamp	Current time in milliseconds. Auto-populated on each page refresh.
clientId	The device client ID. Custom value, up to 64 characters. Use the device MAC address or SN for easy identification.
method	The signature algorithm. Supported algorithms are hmacmd5 and hmacsha1.

Click Generate. The signature parameters are displayed in the Calculation Result section.

The signature parameters include mqttClientId (in the ${clientId}|securemode=2,signmethod=${method},timestamp=${timestamp} format, which can be directly used in the Client ID field of MQTT.fx), username, and password.

Calculate using a Node.js script

Download and decompress the signTool.zip package, then modify and save the following parameters in the mqttSignTool.js file.

Parameter	Example	Description
productKey	a1Ee***	The device certificate saved when you added the device. Device certificate information. View this information on the Device Details page in the console.
deviceName	8Co5***
deviceSecret	bcabcf***
timestamp	2524608000000	The current time in milliseconds.
briefId	12345	Optional. The device client ID. Defaults to `${ProductKey} + '.' + ${DeviceName}`. Example: `var briefId = '12345'`. Important Custom value, up to 64 characters. Use the device MAC address or SN for easy identification.

Download and install Node.js. This example uses Ubuntu 16.04 (64-bit) with node-v16.5.0-linux-x64.tar.gz.
1. Log on to your Linux VM.
2. Download and decompress the package.
```
wget https://nodejs.org/dist/v16.5.0/node-v16.5.0-linux-x64.tar.gz
tar xf node-v16.5.0-linux-x64.tar.gz
cd node-v16.5.0-linux-x64
./bin/node -v
```
  A successful installation returns the version number.
```
v16.5.0
```
3. Add the node and npm commands from node-v16.5.0-linux-x64/bin to global PATH.
```
ln -s /root/node-v16.5.0-linux-x64/bin/npm   /usr/local/bin/
ln -s /root/node-v16.5.0-linux-x64/bin/node   /usr/local/bin/
```
Exit the node-v16.5.0-linux-x64 directory and create a signTool project folder.
```
cd..
mkdir signTool
cd signTool/
```
Upload the modified mqttSignTool.js from step 1 to the signTool directory.

In the signTool directory, download the signature library.

npm install crypto-js
ls

Expected directory contents:

mqttSignTool.js  node_modules  package.json  package-lock.json

Run the mqttSignTool.js script.
```
node mqttSignTool.js
```
The output contains the MQTT signature authentication parameters.

Important
The clientId parameter here maps to mqttClientId, not the device's client ID. MQTT-TLS communication.
```
username:
xxx
clientId:
xxx|securemode=2,signmethod=hmacsha256,timestamp=2524608000000|
passwd:
xxx
```